Pouring sheet for stereotype casting



Aug. 3 1926.

G. M. CLARK, JR

P OURING SHEET FOR STEREOTYPE CASTING Filed Sept 20, 1924 V 1 a v v J I 1 v u w Patented Aug. 3, 1926.

UNITE STTES GEORGE M. CLARK, JR, OF LYNN, MASSACHUSETTS.

POURING SHEET FOR STEREOTYPE CASTING.

Application filed September 20, 1924. Serial No. 738,793.

In the casting of stereotype plates the matrix which carries in intaglio the desired type form is placed in a two part mold and the melted type metal flowed therein against the face of the matrix to form the stereotype plate. In order that a solid casting may be insured a considerable length of gate is employed so that the plate is allowed to solidify under the pressure of a considerable head of molten metal. One side of the gate is formed by one side of the mold, but the opposite side, or that on which the matrix is positioned, is formed by a pouring sheet, the lower end of which is positioned against the inner face of the matrix. This pouring sheet directs the molten metal to the inwardly directed face of the matrix and is intended to prevent the metal from passing down between the matrix and its adjacent mold wall.

As heretofore constructed the lower edge of the pouring sheet has been turned outwardly to form a flange extending at substantially right angles to the body portion of the sheet, this flange engaging the bolster along the upper margin of the matrix. The downward pressure of this flange on the bolster, however, tends to buckle the upper edge of the matrix inwardly and it is found in practice that it often does this to a sufficient extent to cause the adjacent portion of the stereotype plate to be slightly thinner than it should be so that the type is in insufficient relief in the finished plate and fails to print or prints more lightly than the type further removed from this edg In either case defective printing results.

It is also found that the free edge of the flange often fails to bear closely against the matrix, thus permitting the molten type metal to flow therebetween and pass up between the outer face of the pouring sheet and the adjacent wall of the mold forming what is known in the trade as a run back. The flange is very liable to breakage along its juncture with the body of the sheet, particularly when a run back has occurred and when this flange is broken the sheet is ruined. The sheets as thus constructed have therefore often been found unsatisfactory in operation and of short life.

According to the present invention the lower edge of the pouring sheet is so constructed that it bears on the bolster of the matrix only adjacent to its ends and there only for the purpose of fixing the position of the sheet vertically in the mold relative to the matrix. Between these bearing points the lower edge of the sheet is spaced above the bolster and instead of being formed as a flange extending substantially perpendicularly toward the face of the matrix it is formed as a bead having its lower edge curved downwardly to form a resilient lip bearing substantially flat against the face of the matrix above the bolster. This bead is much less liable to breakage than the flange heretofore used and the flat bearing of the lower edge of the sheet against the face of the matrix is much less likely to permit a run back to occur than is the flange edge bearing on the bolster. By relieving the pressure of the plate along the major portion of the length of the bolster there is no tendency to buckle the matrix with a corresponding liability of imperfect printing by the marginal portion of the plate when it is being used. I

It may in some instances, as where large sheets or sheets of cheaper less resilient material are employed, be found desirable to form a rib or corrugation extending outwardly laterally of the pouring sheet somewhat above its lower edge. This rib is formed to engage with the inner wall of the mold when the sheet is in pouring position and not only acts to stiffen the sheet laterally but also as a stopto limit by its contact with the inner wall of the mold the extent of any run back which may by any chance occur.

For a more complete understanding of this invention reference may be had to the accompanying drawings in which Figure 1 is a perspective of one form of pouring sheet, constructed according to this invention.

Figure 2 is a fragmentary plan of a stereotype mold showing the sheet in position.

Figure 3 is a detail vertical section through the mold at the overlapping portions of the sheet and the matrix.

Figure 4 is a. fragmentary perspective of the lower portion of a pouring sheet illustrating a slight modification.

The sheet is formed of thin sheet material preferably of av relatively high carbon steel as shown. at 1, this being shown as bent to curved form so that it may be placed within the outer mold section 2 of the two part stereotype mold as shown in Figure 2 intended for making plates for cylinder presses. The inner section of this mold comprises a substantially semicylindrical portion 3 having its outer face spaced from the inner face of the member 2. The matrix 4, as shown in. Figure 3, is curved to fit within this space and closely against the inner face of the mold section 2 and in the lower portion of the space between the mold sections. The pouring sheet is then inserted in overlapping reiation to the upper edge of the matrix and is clamped in position against the inner wall of the mold section .2 by any suitable means. As is shown in :Figure 2 such means comprise a pair of retaining dogs having flanges 6 behind which the upper corners of the pouring sheet may engage, these dogs being held in position by means of levers '7 having cam enes S riding over cam faces 9 of the pivoted elements 10 to which the dogs 5 are fixed. By this means the sheet is pressed back substantially uniformly against the upper edge of the matrix so that the resilient lip at itslower edge bears firmly thereagainst throughout its length. At 12 in Figure 3 is snown the bolster adjacent to the upper edge of the matrix.

The pouring sheet, as shown in Figure 1, has a bead 15 along its lower edge, this bead forming a rib or corrugation projecting inwardly on the concaved side of the plate, and having its lower edge bent toward parallelism with the main portion of the sheet 1 and slightly outwarei y or rearwardly thereof. At each end of this head are portions 1'? projecting slightly below the intermediate edge portion of the bead, and these may be formed, if .desired, by cu ng away the lower edge of the sheet het en its ends as at 18. The portions 17 engage the upper edge of the bolster 12 to determine the vertical position of the pouring sheet in the mold, while the portion 18 is spaced above the bolster and presses against the forward face ,of the matrix above the bolster as shown at 19 in Figure 3. At the line of engagement of this edge with the matrix it is substantially vertical and is resilient so that it tends to maintain a close joint with the matrix such as to prevent the flow .of melted metal therebetween. As the bead does not bear on .the bolster except at its extreme ends, it has little or no tendency to buckle the matrix so that the plate cast therefrom is of proper thickness at its upper edge .to cause the type adjacent thereto to print :to the same entent as that on other portions thereof. This bead, moreover, less liable to breakage than the usual flange extending perpendicularly to the face of the matrix, particularly if metal has run upwardly between this bead and the matrix as may sometimes occur, though the likelihood of such a. run back of the metal where the lower edge of the pouring sheet resiliently engages the inner face of the matrix ismuch less than in the case of the to those skilled in the art that edge of the head between the ends thereof on a long radius curve as shown at 20 in Fi ure the ends 17 hom left uncut for o a I a 1 supporting the sheet from the boister as in the form shown inFigure 1.

Somewhat above the head 18 the sheet may be provided with an outwardly extend ing head formed preferably by '(7i'l'll2li ing-the sheet. This head or corrugation not only acts to stiffen the sheet, thus preventing it from accidental deformation, particularly at its lower end where it should cngu the maquite accurately, but it also n engage the inner face of the mold section :3 above the upper edge of the matrix at thus acting to limit the extent to which metal may rise which may have passed abore and back of the head 15 in its upward flow or run back between the rear face of the pouring sheet ant. the forward face of the matrix and the inner face of the ,mold section 2.

It will be seen from this construction that .he plate is materially stronger and stiller and less liable to breakage than the plate as heretofore commonly constructed and that the probabilities of run back" are nu terially reduced and when the bead is; employed the extent of any run back, if it occurs, is much more limited.

When the head 25 is not emoloyed it is usually necessary to perform any finishing operations on the lower or side edges or the sheet to produce a suniciently tight fit to prevent run hacks or other leakage of the molten metal, the sheet being suilicicntly rcsilient to conform to the mold with the necessary accuracy.

It is, of course, evident that flat plates could be produced by a suitable mold in which case the pouring sheet would not be curved as shown.

Haying thus described certain embodiments of this invention it should be evident various changes and modifications might be made therein without departing from its spirit or scope as defined by the appended claims.

I claim:

1. A pouring sheet having .its lower edge shaped to bear over .part of its length on the bolster of a matrix, a substantial portion of said edge being spaced from said bolster.

2. A pouring sheet having its lower edge shaped to bear over part of its length on the bolster of a. matrix, a substantial portion of said edge being spaced from said bolster and bearing substantially against the face of said. matrix above the bolster.

31A pouring sheetshaped to bear on the bolster of a matrix adjacent to its ends only.

f. A pouring sheet shaped to bear on the bolster of a matrix adjacent to its ends only, the lower edge of the sheet being formed to engage the face of the matrix above the bolster between said ends.

5. A pouring sheet having a head at its lower ed e terminating in a downwardly extending matrix-engaging margin.

6. A pouring sheet having its lower edge formed to extend rearwardly thereof and to bear on the face of the matrix above the bolster.

7. A pouring sheet having its lower edge formed to bear with resilient pressure against the face of a matrix above the bolster.

8. A pouring sheet having its lower margin formed to engage a matrix, and means above said lower margin for limiting the extent of run back between the sheet and matrix.

9. A. pouring sheet having its lower edge formed to engage a matrix, and having a rearwardly extending rib arranged laterally thereof above said lower edge.

10. A pouring sheet having its lower edge formed to engage a matrix, and having a rearwardly extending corrugation arranged laterally thereof above said lower edge.

11. A pouring sheet having its lower edge formed to extend rearwardly thereof, and having a corrugation arranged laterall thereof above said edge.

12. In combination with a two part mold adapted to receive a matrix against one of said parts in the lower portion thereof, of a pouring sheet insertable in said mold with its lower edge against the matrix in position to direct molten metal between said matrix and the other part of said mold, and means for sealing off said sheet above said matrix to said one part to limit the extent of run back therebetween.

18. In combination with a two part mold a shaped to form a curved printing plate and to receive a matrix therein conformed to the inner face of the outer mold part at its lower end, of a pouring sheet curved to conform to the outer mold part at its upper end and having its lower edge shaped to bear on the inner face of the matrix, said pouring sheet having a corrugation projecting from its convex side and above the upper edge of the matrix and engageable with the outer face of said outer mold part to limit the run back between said sheet and said matrix.

14. In combination with a two part mold adapted to receive a matrix against one of said parts in the lower portion thereof, of a pouring sheet insertable in said mold with it lower edge resiliently engaging the forward face of the matr'x in position todirect molten metal between said matrix and the other part of said mold.

15. in combination with a two-part mold adapted to receive a matrix against one of said parts in the lower portion thereof, of a pouring sheet curved to conform to the outer mold part having its lower edge formed to extend outwardly of the convex face of the sheet, and having a corrugation adjacent said lower edge and extending inwardly, and means for sealing off said sheet above said matrix comprising an outwardly extending rib arranged laterally on the convex face of the sheet and spaced above said corrugation.

In testimony whereof I have affixed my signature.

GEORGE M. CLARK, J R. 

